The present invention relates to an improved machine for continuous twisting and cabling.
In the rest of the description, the machine according to the invention will be designated by the expression "twisting and cabling machine."
For the record, it will be recalled that cabled yarns are articles obtained by assembling at least two filaments by twisting (in a cabling operation), the filaments having previously received a twist in a so-called "twisting" operation. These articles have numerous uses and are used, for example, for providing textile reinforcements to be included in the fabrication of tires, belts, conveyor belts, and the like
The oldest technique for making such cabled yarns, which is still utilized today, consists of making the cabled yarn in two stages, which are carried out on separate machines. The elementary filaments are twisted (in the so-called twisting operation), for example on a twister or a multiple-twisting machine and, then assembled in a cabling operation also on a twisting or multiple-twisting machine. The twist in the cabling operation may be either in the same direction or in the opposite direction to the initial twist of the filaments which constitute the cabled yarn. Furthermore, complementary treatments can be carried out at the same time as these operations, for example a drawing treatment and/or a thermal treatment.
This technique presents numerous disadvantages, the principal ones being:
the risk of defects, because, on the one hand, of the various manipulations to which the windings of the filament are subjected during the different stages; and, on the other hand, tension variations that are produced during the cabling operation; PA1 numerous manual operations because of the various manipulations that such a process requires; PA1 the substantial floor area that is occupied as a result of the utilization of two distinct machines, and because storage areas must be provided between the two phases of the process. PA1 a so-called twisting zone, in which a twist is given to each of the elementary filaments, for example by means of single-twisting or two-for-one twisting spindles; and PA1 a so-called cabling zone, in which several filaments, previously twisted by the twisting operation, are assembled, this assembly being carried out by means of two-for-one twisting spindles or single-twisting ring-and-traveler spindles. PA1 a feeding and twisting section for each elementary filament, on each side of the machine; PA1 means for the return and joining of a predetermined number of elementary filaments thus twisted; PA1 a cabling and winding section; and it is characterized in that the cabling and winding section is common to the two feeding and twisting sections, and it is constituted of spindles disposed side by side, vertically, this being in the vertical plane of symmetry passing between the two feeding and twisting sections. PA1 the cabling and winding spindles are disposed in the central part of the machine, staggered with respect to the twisting spindles; PA1 the twisting spindles are disposed, on each side of the machine, in a single row; PA1 the support frame of the twisting spindles and the cabling spindles is constituted by an assembly in the form of a caisson, including, as seen in transverse cross-section, two lateral levels supporting the twisting spindles, and one central level slightly elevated with respect to the lateral levels; PA1 the means for the return and joining of the twisted elementary filaments, in order to guide them to the cabling section, are disposed in an upper portion of the machine and are fixed on crosspieces attached to columns disposed at each end of the spindle support frame.
To reduce these difficulties, it has been recommended for a very long time to carry out the twisting and cabling operations continuously on a single machine comprising:
The solution utilized most currently, which is similar to that which has been employed in the field of machines for texturization by false twisting, has consisted in providing so-called "three body" machines; which, generally speaking, have the form of a central body, on both sides of which the cabling spindles are mounted side by side; and, disposed facing each of the sides of this central part, and spaced from the latter so as to leave a vacant passage for the operator, a frame on which are mounted the spindles which permit the twisting of the elementary filaments to be carried out, the twisted filaments being guided to the cabling zone while passing above the vacant service area.
Such a type of installation permits continuous twisting and cabling operations to be carried out, but does not practically solve the problem of the floor space that the equipment requires. Moreover, it is apparent that the automation of such equipment is difficult and complex to carry out.
Another solution, which was the object in particular of U.S. Pat. No. 2,979,882 and British Pat. No. 788,242, consists in disposing the twisting spindles and the cabling spindles one above the other, the twisting spindles being generally disposed in the upper part of the machine and mounted horizontally, as illustrated in U.S. Pat. No. 2,979,882, the cabling spindles being mounted vertically on the frame. Such a solution presents the disadvantage of causing the equipment to have a substantial height, which leads to difficulty in the loading of the bobbin holders. Moreover, the twisting spindles are mounted in the upper part of the machine, which can cause difficulties when the machine is operated, and particularly vibrations, which limit the rate of production. Furthermore, the loading and unloading of the bobbins can be automated only with difficulty, with such a design, given the different inclinations of the feeding and receiving bobbins.
Another arrangement of the twisting and cabling spindles has also been considered for a very long time, as shown in U.S. Pat. No. 897,129 (filed Nov. 3, 1906), and French Pat. No. 1,062,599.
In these two documents, the work positions are disposed on both sides of a common support frame, each side of the machine, constructed in this way, including a cabling section and a twisting section, the twisting spindles being disposed at a lower level than the cabling spindles, and toward the outsides of the machine, while the cabling spindles are, for their part, disposed in proximity to the central column of the frame. In this type of equipment, a filament feeding device is disposed between the twisting and cabling parts, this feeder performing the function of a joining component for joining the twisted elementary filaments so that they can be cabled together. Furthermore, breakage detectors are also provided.
In U.S. Pat. No. 897,129, the spindles for the twisting of the elementary filaments are disposed in a single row, while in French Pat. No. 1,062,599, they are disposed in two rows.
In other words, and in summary, it can be said that according to these two documents, on both sides of a common support frame, two distinct assemblies are found, identical and symmetrical, including at the same time, a series of multiple-twisting spindles and a series of cabling spindles.
This type of equipment is satisfactory, but, on the one hand, it is not adapted to permit simple and efficient automation of the mounting and the removal of the bobbins, given that the zone situated above the spindles is not vacant.
Furthermore, owing to its very design, it entails the use of heavy machine frames, since the vibration problem can be serious, particularly in the solution that is the object of French Pat. No. 1,062,599, in view of the elevated position of the cabling assemblies.
Moreover, such a type of equipment is not easy to use, given that it is difficult to make cabled yarns having different numbers of elementary ends, for example to change over from manufacturing a cabled yarn including two elementary ends, to the manufacture of a cabled yarn including three elementary ends.
Accordingly, there has been found, and this is the object of the present invention, an improvement upon the equipment that is the object of the above-cited patents, and more particularly to the type of equipment that is the object of U.S. Pat. No. 897,129, which permits twisting/multiple-twisting machines to be provided; in which, not only are the problems of vibration reduced to a minimum, and the frame structure can be made lighter and simplified; but also which can be used, without any particular modification, to make cabled yarns that may have a variable number of elementary ends, and more particularly, cabled yarns which may indifferently have two or three ends. Furthermore, because of its design, the equipment according to the invention can easily be automated, access to the twisting and cabling spindles being completely free.